Six US Republican congressmen sent a letter to Palestinian Authority President Mahmoud Abbas Thursday, calling him “fully responsible for Hamas’s actions.”

“Just a few weeks ago, you birthed the new Hamas-backed Unity Government,” wrote Doug Lamborn (R-Colorado), David McKinley (R-West Virginia), Steve Stivers (R-Ohio), Marsha Blackburn (R-Tennessee), Trent Franks (R-Arizona), and Michael Grimm (R-New York). “As you and Hamas are now one entity, you are now fully responsible for Hamas’s actions such as this. Moreover, this act of terror is almost certainly a direct result of that reunion. As members of Congress, we expect you to ensure the well-being of the young boys and work steadfastly for their safe return.”

Israel has blamed Hamas for the kidnapping of Naftali Fraenkel, Eyal Yifrach and Gil-ad Shaar, though the Islamist group has denied involvement.

The lawmakers also said the act makes them doubt the sincerity of Abbas’s commitment to peace. “At this time, it is action not words that are of necessity. Furthermore, we are distressed by the continuing expressions of praise and celebrations of the act by the Palestinian population and media.”

The congressmen noted that one of the abducted teens, 16-year-old Naftali Fraenkel, is an American citizen, making this “a matter concerning an American citizen in imminent danger.”

“The suggested implications you and others in the Palestinian media made that compared these boys to terrorist prisoners who are serving time for their atrocities is appalling.”

Republican Congressman Trent Franks, left, speaking with Minister Yuli Edelstein in Jerusalem (photo credit: Raphael Ahren/Times of Israel)

Republican Congressman Trent Franks, left, speaking with Knesset Speaker Yuli Edelstein in Jerusalem. (photo credit: Raphael Ahren/Times of Israel)

The letter was sent to Abbas via the PLO delegation in Washington, DC.

Israeli authorities on Thursday named two West Bank Palestinians as prime suspects in the kidnapping of three Israeli teenagers in the West Bank two weeks ago.

The two alleged abductors, Amer Abu Aysha and Marwan Kawasme, are both known Hamas members. They have been missing from their homes in Hebron’s Hares neighborhood ever since the kidnapping took place on the night of June 12 and are still at large. Israeli security forces have been engaged in a massive operation to find the abducted youths.

Thousands of Israeli troops have searched hundreds of locations in the West Bank and arrested some 400 Palestinians, many from Hamas, including some who were freed in a 2011 prisoner exchange for Hamas-kidnapped Israeli soldier Gilad Shalit.

The three kidnapped Israeli teens, from L-R: Eyal Yifrach, 19, Naftali Fraenkel, 16, and Gil-ad Shaar, 16. (photo credit: courtesy)

The three kidnapped Israeli teens, from L-R: Eyal Yifrach, 19; Naftali Fraenkel, 16; and Gil-ad Shaar, 16. (photo credit: Courtesy)

In recent days, search efforts have focused on an area north of Hebron, where some 1,500 soldiers have been deployed. Some areas are now being searched for the third and fourth time.

The IDF’s Chief of General Staff Benny Gantz said Tuesday that “as time passes, the fear grows,” but stressed that Israel’s working assumption is that the three Israeli teenagers are alive.

Avi Issacharoff, Adiv Sterman, and The Associated Press contributed to this report.